Audit Information

Colorado IRP and IFTA Recordkeeping and Audit Information:
If you are a commercial carrier operating under the terms of your Colorado International Fuel Tax Agreement (IFTA) license and your vehicles are registered using the International Registration Plan (IRP), you are required to keep and maintain certain operating records. These records are necessary to prepare the quarterly IFTA fuel tax return, as well as determine the total distance traveled and the percentage of distance traveled in each jurisdiction.
The IFTA requires records to be maintained for a period of four years from the due date of the IFTA tax return or the date the return was filed, whichever is later. The IRP requires that mileage records be kept for 4 1/2 years on each qualified motor vehicle. These records may be maintained on paper, microfilm/microfiche, digital imaging or other means of storage that have been approved, in writing, by the Colorado Department of Revenue.
*These records must be made available upon request by the department. While the IFTA and IRP recordkeeping requirements are similar, differences and minimal requirements for acceptable source documents are provided in the IFTA and IRP Recordkeeping and Audit Information document.